Question

answer the 5th main first question

Answer 1

Density = mass/ volume

so density of substance is 100/25= 4 gm/cm3

it is denser than water... so it will sink in water.

Answer 2

Solution :-

Given :- Mass of substance = 100
Volume of substance = 25
Density of water = 100g/cm^3
$density = \frac{mass}{volume} \\ \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: = \frac{100}{25} \\ \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: = 4g {cm}^{ -3}$
If the density of the substance is less than water then it will float.
$4g {cm}^{ - 3} < 100g {cm}^{ - 3}$

Hence the substance given in the question will float on water